Double-balloon remodeling for coil embolization of a primitive trigeminal artery variant aneurysm. A case report

Parent Artery Occlusion for Symptomatic Large Internal Carotid Artery Aneurysm with Primitive Trigeminal Artery Variant: A Case Report

Objective

To report a case of symptomatic large cerebral aneurysm of the internal carotid artery (ICA), associated with a primitive trigeminal artery variant (PTAv), which was treated with a balloon occlusion test (BOT) to evaluate ischemic tolerance.

Case Presentation

A 79-year-old woman was diagnosed with a symptomatic large cerebral aneurysm of the ICA bifurcating the PTAv due to diplopia. After confirming the ischemic tolerance of the perfusion area and PTAv by BOT, we performed ICA parent artery occlusion with selective embolization of the PTAv. Postoperative MRI showed no ischemic lesion and the diplopia was resolved.

Conclusion

ICA parent artery occlusion with PTAv selective embolization after evaluation by BOT is useful in the treatment of large aneurysms.

Clinical Importance of the Persistent Primitive Trigeminal Artery in Vascular Lesions and Its Role in Endovascular Treatment

The persistent primitive trigeminal artery (PPTA) extends from the internal carotid artery to the basilar artery between the origins of the anterior inferior cerebellar artery and superior cerebellar artery. PPTAs have complex anatomical characteristics. Salas and Saltzman classifications are most often used in PPTAs. The PPTA can play many roles in vascular lesions, including intracranial aneurysms, brain arteriovenous malformations, trigeminal artery-cavernous fistulas, Moyamoya disease, and large vessel occlusion. For these lesions, surgical treatment is difficult due to the deep location and complex anatomy of the PPTA, but endovascular treatment (EVT) has emerged as a good alternative. Currently, a complete review of the clinical importance of the PPTA in terms of its role in the development and EVT of vascular lesions is lacking. Therefore, we conducted a PubMed search, performed a review of the relevant extracted literature and cataloged our experience with PPTAs. By review, we found that a thorough understanding of the anatomical and angiographic features of this PPTA is of utmost importance when making therapeutic decisions for any of these pathological conditions.

Persistent Trigeminal Artery: Neuroanatomic and Clinical Relevance

INTRODUCTION

Persistent trigeminal artery (PTA) is the most common remnant of primitive circulation communicating the developing carotid and vertebrobasilar junction. Although discovered incidentally, an altered hemodynamic may lead to an increased association of aneurysms, vascular malformations, and stroke. Neurosurgeons should be aware of the presence and significance of PTA when interpreting imaging and planning interventions.

METHODS

We retrospectively reviewed all magnetic resonance angiography and cerebral digital subtraction angiography performed between 2012 and 2017 for the presence of PTA. The radiologic and anatomic details were noted and analyzed along with the clinical profiles. We categorized the radiologic findings with respect to the available classification systems. A review of the available literature was done comparing our results.

RESULTS

We found 33 cases of incidentally detected PTA. The average age of the patients was 45.42 years. The lateral surface of the proximal cavernous internal carotid artery was the most common origin (n = 23). Only 3 cases had a medial/transsellar course. Most cases were Saltzman/Weon type I (19/33). Intracranial aneurysms were associated with 6 patients (18.18%). Trigeminal neuralgia (TN) was a presenting feature in 5 patients. None had a direct neurovascular conflict at the root entry zone.

CONCLUSIONS

Our study is one of the largest to describe the incidence of PTA. We emphasized the importance of PTA to the neurosurgeons; increased association of aneurysms, as a route for intervention in occlusive disease of the posterior fossa; risk of injury and bleeding during transsphenoidal surgery; and the association with TN. However, we found that only PTA variants are likely to be associated with TN because of their cisternal course causing NV conflict.

Persistent trigeminal artery aneurysms: case report and systematic review

Background

The persistent trigeminal artery (PTA) is an adult carotid-basilar anastomosis with debated pathologic aspects, such as its association with brain aneurysms. True trigeminal artery aneurysms are rare vascular anomalies, reported in a few case reports.

Objective

To report our experience with a ruptured trigeminal artery aneurysm and to provide a systematic review of the literature in order to analyse potential links between the anatomic configuration of the PTA and PTA aneurysm (PTAA) type, and implications of each PTAA type for the diagnostic and therapeutic approach.

Methods

We reviewed the medical literature on trigeminal artery aneurysms according to the PRISMA guidelines. Population characteristics, aneurysms features, and PTA type and side were assessed.

Results

40 previously published cases of PTAAs were included in the analysis. The mean age of subjects was 55 years, with a strong female predominance (77%). Four PTAAs were accidentally discovered, while 16 caused compressive symptoms and 20 were ruptured. Successful endovascular treatment was performed in 62% of cases.

Conclusions

PTAAs are rare vascular anomalies, underdiagnosed in the presence of a trigemino-cavernous fistula. Parent vessel occlusion seems to be the best therapeutic option for ruptured or symptomatic unruptured PTAAs in Saltzman type II and III PTAs. Patency of the parent vessel is the main target in Saltzman type I PTA.

Persistent primitive trigeminal artery associated with monocular blindness and external carotid-vertebral artery anastomosis

In this paper, we present 2 rare cases of persistent embryonic anastomoses. In one case, the patient presented with persistent trigeminal artery along with multiple foci of cerebral infarction as well as central retinal artery thrombosis. In the other case, the patient had direct anastomosis of the vertebral artery with ipsilateral external carotid artery as well as pontine infarction, aneurysm, and unilateral hypoplasia of the vertebral artery. The findings in these cases may shed light on the clinical presentation of such persistent anastomoses and aid their detection in clinical settings.